1. Field of the Invention
The invention is directed to purified and isolated novel murine and human kinase polypeptides and fragments thereof, the nucleic acids encoding such polypeptides, processes for production of recombinant forms of such polypeptides, fragmented peptides derived from these polypeptides, antibodies generated against these polypeptides, methods of identifying activators and inhibitors of the activity of these kinases, and therapeutic and diagnostic uses thereof.
2. Background
Cells respond to external signals and internal signals, such as those produced by disease conditions, by activating cellular signaling pathways. Cellular signaling often involves a molecular activation cascade, during which a receptor propagates a ligand-receptor mediated signal by specifically activating intracellular protein kinases which phosphorylate target substrates. These substrates can themselves be kinases which become activated following phosphorylation.
The eukaryotic protein kinases make up a large and rapidly expanding family of proteins related on the basis of homologous catalytic domains. Spurred by the development of gene cloning and sequencing methodologies, distinct protein kinase genes have been identified from a wide selection of invertebrates and lower eukaryotes, including Drosophila, Caenorhabditis elegans, Aplysia, Hydra, Dictyostelium, and budding (Saccharomyces cerevisiae) and fission (Schizosaccharomyces pombe) yeast. Homologous genes have also been identified in higher plants. Protein kinases, however, are not limited to the eukaryotes. Enzyme activities have been well documented in prokaryotes, but the prokaryotic protein kinase genes are not obviously similar to those of the eukaryotes.
Given the important function of kinases in general, there is a need in the art for additional members of the kinase family. In addition, in view of the continuing interest in protein research, the discovery, identification, and roles of new proteins, such as protein kinases, are at the forefront of modem molecular biology and biochemistry. Despite the growing body of knowledge, there is still a need in the art for the identity and function of proteins having kinase activities. In addition, because there is an unmet need for therapeutic compounds which modulate kinase activity and because protein kinases are useful biochemical reagents, there is also need in the art for the continued discovery of unique members of the protein kinase family and potential therapeutic targets thereof.